Proximity sensors are used in myriad devices, systems, and environments to sense the position or relative proximity of one or more objects. For example, proximity sensors may be used in manufacturing, security, robotic, and vehicular environments to determine the position of various objects and, in some instances, control one or more components. Proximity sensors are typically configured as binary-type switches that open or close an electrical circuit when an object contacts, or comes within a predetermined distance of, the sensor.
Proximity sensors are also variously configured and sense object position or relative proximity using various physical phenomena. For example, proximity sensors have been configured to sense object position or relative proximity based on capacitance, inductance, acoustics, electromagnetism, and infrared and optical light. Although each of these types of proximity sensors are generally accurate, safe, and reliable, each suffers certain drawbacks. For example, these sensor types can be susceptible to electromagnetic interference (EMI) and/or sensitive to temperature variations.
In addition to the above-noted drawbacks associated with proximity sensors, when these sensors, and other sensors that use the same or different type of physical phenomena, are implemented as part of a sensing suite, many times different phenomena are used to provide feedback on the various properties being sensed (e.g., speed, pressure, position, etc.). This can increase the complexity in the interface electronics and hinder economies of scale in sensing element and system production.
Hence, there is a need for a proximity sensor that is accurate, safe, and reliable, and that is less susceptible to EMI and/or less sensitive to temperature variations, at least as compared to current devices. There is also a need for a sensing system with interface electronics that are relatively less complex and/or do not hinder production economies of scale. The present invention addresses one or more of these needs.